What you basically have to do is remove UC3 from your VC1541 (you can reuse the MCS6522 from there on the board) and put the modded board there.

Then you have to remove UB4 with a EPROM with the modded firmware.  You need a 2364-EPROM for this, but you can solder an adaptor for 2764-compatibility.

Partlist:

C1, C2, C3, C4   100nF ceramic

D1, D2, D3   diode 1N4148

R1, R2   3,3 kOhm resistor

IC1    MCS6522 (from VC1541)

IC2    SN75160

IC3   SN75161

IC4     74LS136D

JP1, JP2     2,54mm 2 Pin single row pin header

S1    2,54mm 20 Pin single row pin header, 2 pieces, back side for connection VC1541

S2    2,54mm 24 Pin header double row angled

Pin numbering S2 (looking on the pcb, S2 lower right):

Upper row 1 to 12 from left to right, lower row 13 to 24 from left to right

Pinout (1-24):

D1, D2, D3, D4, EOI, DAV, NRFD, NDAC, IFC, SRQ, ATN, GND, D5, D6, D7, D8, REN, Rest GND

Connect S2 like shown with 24-pin Centronic-Plug

Good luck!